JPH08234494A - Color toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE: To obtain a color toner giving a clear color, excellent in heat and light resistances and excellent also in transparency for OHP. CONSTITUTION: A compsn. contg. at least a polymerizable monomer, wax and a colorant is directly polyermized in an aq. medium to obtain the objective color toner having a wt. average diameter of <=9μm. The wax contains ester wax and the colorant has a skeleton represented by the formula.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic charge image developing color toner for developing an electrostatic charge image formed in an electrophotographic method, an electrostatic printing method or the like.

More specifically, it relates to a yellow toner obtained by aqueous suspension polymerization of a monomer composition containing at least a release agent and a colorant.

[0003]

2. Description of the Related Art Conventionally, a developer using an electrophotographic process has been prepared by adding a colorant, a charge control agent and a release agent to polyester, styrene-acryl, epoxy resin, etc., melt-kneading them, and uniformly dispersing them. A production method by a pulverization method is generally used in which the fine / coarse powder developer is pulverized to a predetermined particle size and excess excess / coarse powder developer is removed using a classifier.

However, with the recent improvement in image quality, it has become necessary to further reduce the particle size of the developer.

However, as the particle size measured by a Coulter counter becomes 9 μm or less, uniform dispersion of the raw materials used, which has not been a problem in the past, highly efficient pulverizability, and classification of the developer into a sharp particle size distribution. Tends to be extremely difficult.

In order to overcome the problems of the developer due to the crushing method, Japanese Patent Publication Nos. 36-10231 and 43-1.
No. 0799 and Japanese Patent Publication No. 51-14895, a method for producing a developer by a suspension polymerization method is proposed.
In the suspension polymerization method, a polymerizable monomer, a colorant, a polymerization initiator, and optionally a crosslinking agent, a charge control agent, and other additives are uniformly dissolved or dispersed to obtain a monomer composition. Then, this monomer composition is dispersed in a continuous phase containing a dispersion stabilizer, for example, an aqueous phase by using a suitable stirrer, and a polymerization reaction is simultaneously carried out to obtain a developer having a desired particle size. Is the way.

In this manufacturing method, it is not necessary to impart brittleness to the developer because it does not go through the crushing step, and a large amount of the low softening point substance which cannot be used in the conventional crushing method can be used. The selection range of materials such as In addition, it is difficult to expose the release agent or colorant, which is a hydrophobic material, to the surface of the developer particles.
It has attracted attention recently because of its characteristics such as less contamination of transfer rollers and fixing devices.

Further, in recent years, digital full-color copying machines and printers have been put into practical use, and toner image fidelity,
It has become necessary to further improve features such as releasability and color reproducibility.

As the required quality required for image fidelity,
Digital full-color copiers require a larger amount of developer to be transferred from the photoconductor to the transfer material than black-and-white copiers, and in order to support higher image quality in the future It is expected that there will be a demand for smaller particle sizes.

From this point of view also, the polymerization method, which can relatively easily produce a developer having a sharp particle size distribution and a fine particle size, has excellent characteristics.

Further, as the printers and copiers in the future are becoming faster and full-colored, improvement in low-temperature fixing property is also an important factor.

In a full-color copying machine, it is essential that the multicolor toners are sufficiently mixed in the fixing step to obtain color reproducibility and transparency of an OHP image.
Generally, a sharp melt low molecular weight resin is desired.

Generally, the black toner uses a crystalline material such as polyethylene wax or polypropylene wax having a relatively high releasability in order to improve the high temperature offset resistance at the time of fixing. When the above wax is used as the above, the transparency of the release agent is markedly impaired when output to the OHP due to the high crystallinity of the release agent.

Therefore, the high temperature offset resistance is eventually improved by uniformly applying silicone oil or the like to the heat fixing roller without adding a releasing agent as a color toner constituent component. However, the output transfer member thus obtained has an undesired discomfort when used by the user, since excess silicone oil or the like adheres to the surface of the output transfer member.

Therefore, a developer for oilless fixing in which a large amount of a low softening point substance is contained in the developer has been studied, but it is excellent in low temperature fixing property and transparency, and at the same time high temperature offset resistance. No satisfactory developer has been obtained yet.

Further, since it becomes more difficult to uniformly encapsulate the release agent in the pulverization method as the toner has a fine particle diameter, encapsulation of the release agent in the fine particle size has become a major problem.

The required quality required for special colors such as color reproducibility is further improvement in color tone, saturation, coloring power, etc., and most of them are affected by the modification of the colorant itself.

In particular, since yellow toner is in great demand as a color to be used for skin tones, many toners such as mono / disazo type, anthraquinone type, quinoline type, isoindolinone type, pyridone type, methine type have been used as toners. It has been disclosed as a dye for use.

For example, JP-A-62-54275 describes a disazo pigment, and JP-A-1-227162.
Japanese Unexamined Patent Publication No. Hei 4-
Japanese Patent No. 241363 describes methine dyes, and Japanese Patent Application Laid-Open No. 19535/1993 describes isoindolinone pigments.

Among these colorants, the pigment has a good melt affinity to the binder resin and a good light resistance even in an aqueous polymerized toner, and a toner having excellent charging characteristics and color tone can be obtained.
However, in order to obtain an image that is more faithful to the original while satisfying the low temperature fixing property and transparency, further image durability / environmental stability, affinity with a release agent, color tone / saturation, etc. Improvement is desired.

Further, in recent years, as a further application of the electrophotographic technique, a movement for retransferring an image to a steel material, a cloth or the like has occurred, but such a processed product is conventionally used because it is easily used outdoors. The above heat resistance and light resistance are required.

From these viewpoints, JP-A-5-1953 is particularly preferable.
No. 8, JP-A-6-230607, and JP-A-6-230607.
Pigment as disclosed in Japanese Patent No. 266163.
The disazo pigment represented by Yellow 180 has excellent heat resistance, but when it is used in a polymerized fine particle toner having a particle size of 9 μm or less, it tends to appear on the toner surface due to the characteristics of its polar group and has a high charging property. And so on, we haven't got enough satisfaction.

[0023]

SUMMARY OF THE INVENTION An object of the present invention is to provide a color toner for developing an electrostatic charge image, which solves the above-mentioned drawbacks.

That is, an object of the present invention is to provide a color toner for developing an electrostatic charge image, which has excellent OHP transparency and environmental stability and has charging characteristics.

Another object of the present invention is to provide a color toner for electrostatic image development which is excellent in heat resistance and light resistance.

A further object of the present invention is to provide a color toner for developing an electrostatic charge image, which can obtain extremely vivid colors.

[0027]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner obtained by directly polymerizing a composition containing at least a polymerizable monomer, a wax and a colorant in an aqueous medium. It is achieved by having a weight average diameter of 9 μm or less, the wax having an ester wax, and the colorant containing a compound having a skeleton represented by the following structural formula.

[0028]

Embedded image

The present invention will be described in detail below.

The present invention achieves the object of the present invention by combining the pigment of the present invention classified into Pigment Yellow 180 with a specific wax.

This is because the ester group in the wax has an affinity for the functional group of the pigment having the structure of the present invention, so that the pigment is taken up by the wax having hydrophobicity and buried in the toner. I think it will happen.

Further, unlike the other pigments, the colorant of the present invention usually has needle crystals, but since this crystal structure improves the dispersibility with the wax, it is more vivid than toners using other pigments. Toner with excellent transparency and transparency is obtained.

From the viewpoint of hue and transparency, the pigment of the present invention is preferably contained in the toner in an amount of 0.2 to 15% by weight, and the secondary particles in the toner have a minor axis of 0.1.
It is preferable that primary particles having a diameter of less than μm and a major axis of 0.15 to 2 μm are mainly dispersed.

The pigment of the present invention can be combined with other conventionally known colorants for improving the tint, but the effect of inhibiting the aqueous phase transition by the ester wax tends to be greatly inhibited by the other colorants. Therefore, the pigment 100 of the present invention
It is preferably less than 20 parts by weight with respect to parts by weight.

In the present invention, an improvement in charging property is achieved by combining a wax having an ester group with the pigment of the present invention.

From this point of view, the wax of the present invention more preferably has at least one long chain ester moiety having 15 or more carbon atoms, and more preferably 15 or more and 30 or less.

When the number of carbon atoms is less than 15, the surface of the pigment is modified, but the water phase transfer property of the pigment cannot be suppressed, and the charge stability of the toner deteriorates. When the carbon number is more than 30, the plasticizing effect of the wax on the resin becomes too large and the fixability is lowered.

Further, in recent years, the need for a full-color double-sided image has been increasing, and in forming a double-sided image, the toner image on the transfer paper formed first on the front surface is also formed on the rear surface. There is a possibility of passing through the heating portion of the fixing device again, and it is necessary to more fully consider the high temperature offset resistance of the toner. Therefore, in the present invention, addition of a large amount of ester wax is essential.

Therefore, the ester wax of the present invention is required to have releasability and transparency in addition to modification of the pigment, and it is preferable to add 5 to 30% by weight of the ester wax to the toner.

If it is added in an amount of less than 5% by weight, sufficient reformability is not exhibited, and further, the image on the back side tends to show an offset phenomenon when fixing a double-sided image. On the other hand, if it exceeds 30% by weight, during the production of the toner, for example, in the production by the pulverization method, the device fusion or the toner fusion tends to occur,
Also in the production by the polymerization method, toner particles are likely to coalesce with each other at the time of granulation and the impact resistance against the drum is lowered, so that filming is likely to occur.

As a means for modifying the pigment of the present invention by adding an ester wax, known methods such as master batching can be used in advance, but modification, dispersibility, re-aggregation, etc. In order to obtain the effect of the above, when both are added, 10 parts by weight of the ester wax is added to 100 parts by weight of the pigment.
It is desirable to add it in a ratio of 0 to 3000 parts by weight.

In the present invention, the ester wax used is preferably a compound having a main component maximum peak value measured according to ASTM D3418-8 of 40 to 90 ° C. When the maximum peak is less than 40 ° C., the self-aggregating force of the low softening point substance becomes weak, and as a result, the high temperature offset resistance becomes weak, which is not preferable for a full color toner. On the other hand, when the maximum peak exceeds 90 ° C., the fixing temperature becomes high, and it becomes difficult to appropriately smooth the surface of the fixed image, which is not preferable in terms of color mixing. Further, when the toner is obtained by the direct polymerization method, since the granulation / polymerization is carried out in an aqueous system, if the temperature of the maximum peak value is high, the low softening point substance mainly precipitates during granulation, which disturbs the suspension system. Not preferable.

In measuring the temperature of the maximum peak value of the present invention,
For example, Perkin Elmer DSC-7 is used. The melting point of indium and zinc is used to correct the temperature of the device detection unit, and the heat of fusion of indium is used to correct the amount of heat. An aluminum pan was used as a sample and an empty pan was set as a control, and the temperature rising rate was 10 ° C./min. Was measured.

Structural formulas of typical compounds of specific ester waxes preferable in the present invention are shown below as general structural formulas, general structural formulas and general structural formulas.

[0045]

[Chemical 6]

(A, b: integers from 0 to 4, a + b
= 4 R ₁ , R ₂ : an organic group having an integer of 1 to 40 carbon atoms, and a carbon number difference between R ₁ and R ₂ is 3 or more m, n: an integer of 0 to 25, m And n cannot be 0 at the same time. )

[0047]

[Chemical 7]

(A, b: integers from 0 to 4, a + b
= 4, b ≠ 0 R ₁ : an organic group having an integer of 1 to 40 carbon atoms m, n: an integer of 0 to 25, and m and n are not 0 at the same time. )

[0049]

Embedded image

(A, b: integers from 0 to 3 and 1≤a
+ B ≦ 3 R ₁ , R ₂ : an organic group having an integer of 1 to 40 carbon atoms, and the difference in carbon number between R ₁ and R ₂ is 3 or more R ₃ : hydrogen atom, organic having 1 or more carbon atoms Basis. However, a
When + b = 2, one of R ₃ is an organic group having 1 or more carbon atoms, k: an integer from 1 to 3, m and n: an integer from 0 to 25, and m and n are 0 at the same time. It never happens. )

The ester wax preferably used in the present invention preferably has a hardness of 0.5 to 5.0.
The hardness of ester wax is 20mmφ in diameter and 5m in thickness.
It is a value obtained by measuring the Vickers hardness using a dynamic ultra-fine hardness meter (DUH-200) manufactured by Shimadzu Corporation after producing a cylindrical sample of m. Measurement condition is 0.5g
Of 10 μm under the condition of load speed of 9.67 mm / sec
After the displacement, it is held for 15 seconds, and the obtained dent shape is measured to determine the Vickers hardness. The hardness of the ester wax preferably used in the present invention has a value of 0.5 to 5.0. If the material has a hardness of less than 0.5 and has a low softening point, the pressure dependency and the process speed dependency of the fixing device become large, and the high temperature offset resistance effect is apt to be insufficiently expressed. Poor stability,
Since the self-aggregating force of the release agent itself is small, the modifying property of the pigment of the present invention tends to be insufficient.

The following compounds may be mentioned as specific compounds.

[0053]

[Chemical 9]

Further, in the present invention, it is preferable from the viewpoint of pigment modification that the ester wax is encapsulated in the outer shell resin layer by observing the toner cross-section layer using a transmission electron microscope (TEM).

As means for encapsulating the ester wax, a method of seed polymerization using suspension-polymerized particles as nuclei as described in JP-A-59-6287 or JP-A-61-46 is used.
Many methods such as a method of adding a polar resin having poor compatibility with an ester wax as disclosed in Japanese Patent No. 955 are disclosed, but what is the method that can be confirmed by the method of the present invention by these known methods? Any means may be used.

Among the known methods, the present inventors have found that the method of adding a polar resin promotes uneven distribution of the ester wax, and even if combined with any known method, the effect is more exerted. In the present invention, the addition of polar substances is considered essential.

As the polar resin used in the present invention, commonly used materials such as a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a saturated polyester resin and an epoxy resin are preferably used. .

As a specific method for measuring the tomographic plane of the toner in the present invention, the toner is sufficiently dispersed in a room temperature curable epoxy resin and then cured in an atmosphere of a temperature of 40 ° C. for 2 days to obtain a cured product. After ruthenium tetraoxide and, if necessary, osmium tetraoxide are used together for dyeing, a microtome equipped with diamond teeth is used to cut out flaky samples and the tomographic morphology of the toner is measured using a transmission electron microscope (TEM). did. In the present invention, it is preferable to use the ruthenium tetroxide dyeing method in order to make a contrast between materials by utilizing a slight difference in crystallinity between the low softening point substance used and the resin constituting the outer shell. A typical example is shown in FIG. It was clearly observed that the low softening point substance was encapsulated by the outer shell resin.

Further, in the present invention, it is preferable that the shape factor SF-1 measured by Luzex is 100 to 130 in order to secure transferability and developability during high speed copying.

SF-1 indicating the shape factor in the present invention means 100 toner images are randomly sampled using FE-SEM (S-800) manufactured by Hitachi, Ltd., and the image information is taken from the Nicolet Corporation through an interface. The value calculated by the following formula was defined as SF-1 in the present invention by introducing it into an image-manufacturing analyzer (Luzex3) for analysis.

[Definition formula of SF-1]

[0062]

[Equation 1]

[Wherein MXLNG represents the absolute maximum length of the developer on the image, and AREA represents the projected area of the developer. ]

A developer shape having a developer shape factor SF-1 of more than 130 gradually changes from a spherical shape to an indefinite shape, and at the same time, the transfer efficiency decreases, so that a large amount of toner remains untransferred on the drum. As a result, filming is likely to occur during high-speed copying.

In the case of the toner of the present invention, the shape factor SF-1 of the toner is 100 to 130, more preferably 10 in order to secure practical filming resistance and transfer / developability.
A substantially spherical toner of 0 to 120 is preferable, and in order to faithfully develop finer latent image dots for higher image quality, the particle size is smaller than that of the developer, specifically, measured by a Coulter counter. A toner having a weight average diameter of 9 μm or less, more preferably 4 μm to 8 μm and a number variation coefficient of 35% or less is preferable.

The polymerizable monomer used in the toner of the present invention includes styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene,
Styrene monomers such as p-ethylstyrene, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, acrylic acid 2
-Acrylic esters such as ethylhexyl, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n methacrylate -Amount of methacrylic acid ester such as octyl, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc. and other acrylonitrile, methacrylonitrile, acrylamide, etc. The body.

These monomers may be used alone or as a mixture. Among the above-mentioned monomers, it is preferable to use styrene or a styrene derivative alone or in combination with other monomers, from the viewpoint of developing characteristics and durability of the toner.

In order to control the molecular weight,
Known crosslinking agents and chain transfer agents may be added, and the preferable addition amount is 0.001 to 15% by weight.

Further, a resin may be added to the monomer system for polymerization. For example, a monomer is water-soluble and cannot be used because it dissolves in an aqueous suspension and causes emulsion polymerization, so that it cannot be used for amino acids, carboxylic acid groups, hydroxyl groups, sulfonic acid groups, glycidyl groups, nitrile groups and other hydrophilic functional groups. When it is desired to introduce monomer components into the toner, a random copolymer of these and a vinyl compound such as styrene or ethylene,
It can be used in the form of a copolymer such as a block copolymer or a graft copolymer, or in the form of a polycondensate such as polyester or polyamide, or a polyaddition polymer such as polyether or polyimine.

The amount used is preferably 1 to 20% by weight. The average molecular weight of the high molecular weight polymer containing these polar functional groups is preferably 5,000 or more.
When it is less than 5,000, particularly 4,000 or less, the present polymer is likely to concentrate near the surface, which is unfavorable since it tends to have a bad influence on the developability and blocking resistance. Also,
When a polymer having a molecular weight different from the molecular weight range of the toner obtained by polymerizing the monomer is dissolved in the monomer and polymerized, a toner having a wide molecular weight distribution and high offset resistance can be obtained.

As the polymerization initiator used in the polymerization method, any suitable polymerization initiator, for example, 2,
2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,
Azo-based or diazo-based polymerization initiators such as 1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile and azobisisobutyronitrile, benzoyl Examples thereof include peroxide type polymerization initiators such as peroxide, methyl ethyl ketone peroxide, diisopropyl peroxy carbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide and lauroyl peroxide. These polymerization initiators are 0.5 to 20 of the polymerizable monomer.
The addition amount of wt% is preferable, and they may be used alone or in combination.

In the polymerization method, known surfactants and organic / inorganic dispersants can be used as the dispersion stabilizer. Among them, the inorganic dispersant is unlikely to produce harmful ultrafine powder, and the dispersion stability is obtained due to its steric hindrance. Therefore, stability is not easily deteriorated even when the reaction temperature is changed, cleaning is easy, and the toner is not adversely affected. Therefore, it can be preferably used. Examples of such inorganic dispersants include polyvalent metal phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate, carbonates such as calcium carbonate and magnesium carbonate, and inorganic salts such as calcium metasilicate, calcium sulfate and barium sulfate. Examples thereof include inorganic oxides such as salts, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite, and alumina.

These inorganic dispersants are composed of the polymerizable monomer 10
It is desirable to use 0.2 to 20 parts by weight per 0 parts by weight, but it is difficult to generate ultrafine particles, but it is somewhat difficult to atomize the toner, so 0.001 to 0.1 parts by weight Some surfactants may be used together.

As the surfactant, for example, sodium dodecylbenzenesulfate, sodium tetradecylsulfate, sodium pentadecylsulfate, sodium octylsulfate,
Examples thereof include sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated in an aqueous medium. For example, in the case of calcium sulfate, a water-insoluble calcium phosphate can be produced by mixing an aqueous solution of sodium sulfate and an aqueous solution of calcium chloride under high-speed stirring, and more uniform and fine dispersion is possible.

In the present invention, it is desirable to add a charge control agent to the toner material for the purpose of controlling the chargeability of the toner. Examples of these charge control agents include nigrosine dyes, triphenylmethane dyes, quaternary ammonium salts, quaternary ammonium salts, guanidine derivatives, imidazole derivatives, amine-based and polyamine-based compounds as positive charge control agents, and negative charge control agents. Examples include metal-containing salicylic acid compounds, metal-containing monoazo dye compounds, urea derivatives, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, and the like. The addition amount of these charge control agents is preferably 0.1 to 10% by weight.

As an additive for imparting various toner characteristics, from the viewpoint of durability in the toner or when added to the toner, the particle diameter is 1/10 or less of the volume average diameter of the toner particles. Is preferred. What is the particle size of this additive?
It means the average particle size of the toner particles obtained by observing the surface thereof with an electron microscope. As the additives for imparting these characteristics, for example, the following ones are used.

1) Flowability-imparting agents: metal oxides (silicon oxide, aluminum oxide, titanium oxide, etc.), carbon black, fluorinated carbon, etc. Those subjected to a hydrophobic treatment are more preferable.

2) Abrasive: metal oxide (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide, etc.), nitride (silicon nitride, etc.), carbide (silicon carbide, etc.), metal salt (calcium sulfate, etc.) , Barium sulfate, calcium carbonate, etc.) etc.

3) Lubricants: Fluorine-based resin powders (vinylidene fluoride, polytetrafluoroethylene, etc.), fatty acid metal salts (zinc stearate, calcium stearate, etc.), etc.

4) Charge controllable particles: metal oxides (tin oxide, titanium oxide, zinc oxide, silicon oxide, aluminum oxide, etc.), carbon black, etc.

These additives are used in an amount of 0.1 to 10 parts by weight, preferably 100 parts by weight of the toner particles.
0.1-5 parts by weight are used. These additives may be used alone or in combination.

When a carrier is used as the developer, any conventionally known one can be used. For example, it is a magnetic substance such as iron, cobalt, or nickel, an alloy or mixture thereof, or a surface of which is coated.

General production examples of color toners containing the colorant of the present invention will be given.

A release agent, a colorant, a charge control agent, a polymerization initiator, and other additives are added to the polymerizable monomer, and a media disperser such as a homogenizer, an ultrasonic disperser, a ball mill, a sand mill and an attritor. The monomer system uniformly dissolved or dispersed by the above method is dispersed in an aqueous phase containing a known dispersion stabilizer by a usual stirrer, homomixer, homogenizer or the like.

Granulation is preferably carried out by adjusting the stirring speed and time so that the monomer droplets have a desired toner particle size, generally 30 μm or less. After that, stirring is performed to the extent that the particle state is maintained and the particles are prevented from settling due to the action of the dispersion stabilizer.

The polymerization temperature is set to 40 ° C. or higher, generally 50 to 90 ° C. to carry out the polymerization. In addition, the temperature may be raised in the latter half of the polymerization reaction, and in the latter half of the reaction or the end of the reaction in order to remove unreacted polymerizable monomers and by-products that may cause odor during toner fixing. The aqueous medium may be partially distilled off later.

After the reaction is completed, the produced toner particles are collected by washing and filtering and dried.

Depending on the case, classification is performed with a classifier, and further, silica or the like is dispersed in the classified product with a Henschel mixer or the like.

The particle size distribution measurement in the present invention will be described.

As a measuring device, a Coulter counter T
A-II type (manufactured by Coulter Co.)
Interface that outputs volume average distribution (made by Nikkaki)
And CX-1 personal computer (Canon)
Connected to the electrolyte using 1% sodium chloride using primary sodium chloride.
An aqueous Cl solution is prepared.

As a measuring method, the electrolytic aqueous solution 100 to 1 is used.
To 50 ml, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant, and 0.5 to 50 mg of a measurement sample is further added.

The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the particle size distribution of particles of 2 to 40 μm was measured by the Coulter Counter TA-II type using an aperture of 100 μm as an aperture. Is measured to obtain a volume average distribution and a number average distribution. The weight average particle diameter is obtained from the volume average distribution and the number average distribution thus obtained.

Regarding the light resistance, JIS K-7
102 (Method A, FV type). That is, the test image was irradiated with carbon arc lamp light under the condition that no water spray was applied, and its discoloration was measured by using a blue scale and evaluated.

The fixing property, anti-offset property, and
The evaluation method of the mixed color area and the transparency is as follows.

1) Fixability, Offset Resistance, and Color Mixing Region First, a proper amount of the above external additive is externally added to the toner containing the ester wax of the present invention to obtain a developer. The unfixed image of the obtained developer is prepared by a commercially available copying machine.

When the toner is black toner, the fixing property and offset resistance are evaluated by a heat roller external fixing device having no oil coating function.

Further, in the case of a mono-color toner or a full-color toner, in addition to a heat roller external fixing device having no oil coating function, a commercially available full-color copying machine such as CLC is used.
Using a fixing device of -550 (manufactured by Canon Inc.), apply some oil uniformly to the fixing roller (for example, 0.02 g / A4).
Then, the fixability, offset resistance, and color mixture area are evaluated, and a fixed image for transparency evaluation is obtained.

At this time, as the roller material, a fluorine-based material is used for both the upper and lower parts. As for the fixing conditions, when the transfer material is SK paper (manufactured by Nippon Paper Industries Co., Ltd.), the nip is 6.5 mm and the process speed is 120 mm / s.
ec, when the transfer material is an OHP sheet (Pictrico Trapen for copier / Asahi Glass Co., Ltd.), the nip is 6.5 m
m, the process speed is 30 mm / sec, and the temperature is adjusted every 5 ° C. within the temperature range of 80 ° C. to 230 ° C.

The fixing property is such that a fixed image (including a low-temperature offset image) is applied with a load of 50 g / cm ² on sillbon paper [Lenz Cleaning Paper “das”].
per (R) "(Ozu Paper Co. Lt
The temperature at which the density reduction rate before and after rubbing is less than 10% is determined as the fixing start point.

With respect to the offset resistance, the temperature at which the offset disappears visually is taken as the low temperature offset starting point, and the temperature is raised.
The highest temperature without offset is the high temperature offset end point.

Further, in the color mixture area, an image in the non-offset area is processed by a handy gloss meter gloss checker-IG-310.
The gloss value is measured using (Horiba Seisakusho) and the gloss value is 2
The area is determined by defining it as the maximum value above.

2) Transparency The transmittance and the haze value (haze) for each toner amount per unit area of the obtained fixed image were measured to obtain an image density of 1.5.
The transparency was evaluated using the numerical value in. The method of measuring the transmittance and haze will be described below.

The transmittance was measured by Shimadzu's own spectrophotometer UV.
2200 (manufactured by Shimadzu Corporation) is used, the transmittance of the OHP film alone is set to 100%, and the transmittance at the maximum absorption wavelength at 600 nm is measured.

In addition, the haze is measured by the haze meter ND.
It measured using H-300A (made by Nippon Coloring Industry Co., Ltd.).

[0106]

The present invention will be described in detail with reference to examples.

Example 1 A 0.1 M Na ₃ PO ₄ aqueous solution and a 1 M CaCl ₂ aqueous solution are prepared. A 2-liter four-necked flask equipped with a high-speed stirring device TK-Homomixer was charged with ion-exchanged water 710.
Parts by weight and 450 parts by weight of a 0.1 mol-Na ₃ PO ₄ aqueous solution were added to adjust the rotation speed to 12,000, and the mixture was heated to 65 ° C. 68 parts by weight of a 1.0 mol-CaCl ₂ aqueous solution was gradually added to the mixture to form a fine water-insoluble dispersant Ca ₃ (P
A dispersion medium system containing O ₄ ) ₂ was prepared. On the other hand, the dispersoid system is styrene monomer 165 parts by weight n-butyl acrylate monomer 35 parts by weight

[0108]

[Chemical 10]

Saturated polyester 10 parts by weight (terephthalic acid-propylene oxide modified bisphenol A acid value 15, peak molecular weight 6000) Metal salicylate compound 2 parts by weight Compound (4) (maximum peak value 64.4 ° C.) 40 parts by weight

The above mixture was dispersed for 3 hours using an attritor, and then 10 parts by weight of 2,2'-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator was added to the dispersion medium. 1 while keeping the rotation speed
Granulated for 5 minutes. After that, the stirrer was changed from a high-speed stirrer to a propeller stirrer, the internal temperature was raised to 80 ° C., and the polymerization was continued at 50 rpm for 10 hours. After the polymerization was completed, the slurry was cooled and diluted hydrochloric acid was added to remove the dispersant.

By further washing and drying, the weight average diameter of the yellow toner measured by a Coulter counter is 6
The number variation coefficient is 28% at μm, and SF-1 is 105%.
Met. A schematic view of a tomographic photograph of the obtained yellow toner is shown in FIG. This shows a structure in which the compound (4) which is a low softening point substance is covered with the outer shell resin. 2% of hydrophobized titanium oxide was externally added to the obtained toner to obtain a toner having excellent fluidity.

To 7 parts by weight of this toner, 93 parts by weight of a ferrite carrier coated with an acrylic resin was mixed, and a full color copying machine CLC5 manufactured by Canon Inc. was used as a developer.
It was 23 ° C and 6
Under the condition of 0%, a stable and clear yellow image was obtained without lowering the developability even after running 20,000 sheets.

The copy was also excellent in light resistance and was of the 7th grade, and was excellent in fixability and OHP transparency.

Further, a copying durability test was carried out at 30 ° C. under high temperature and high humidity of 80% for 10,000 sheets, but no fog or the like occurred.

Comparative Example 1 In the formulation of Example 1, the colorant was a disazo pigment (C.I.
I. Pig. Yellow 17) The same operation as in Example 1 was performed except that the amount was changed to 3.5 parts by weight, and the weight average diameter was 5.
8 μm toner (number variation coefficient 35%, SF-1 = 11
2) was prepared and evaluated. Compared with Example 1, in particular, the OHP image was inferior in color saturation and an image having a dull color tone was obtained.

The light resistance was grade 5, and was inferior to that of Example 1 in the heat resistance test for 10 days at 100 ° C.

Comparative Example 2 The same procedure as in Example 1 was carried out except that 50 parts by weight of paraffin wax (maximum peak value 73.1 ° C.) was used in place of the ester wax in the formulation of Example 1, and the weight average was obtained. Toner with a diameter of 6.6 μm (number variation coefficient 34%, SF-1 =
110) was prepared and evaluated. Compared with Example 1, there was no difference under the conditions of 23 ° C. and 60%, but 30
At 10,000 sheets durability under high temperature and high humidity of 80 ° C., the chargeability could not be obtained, and fog and the like occurred due to the durability and did not reach the practical level.

The image was opaque with no OHP transparency.

Comparative Example 3 A toner having a weight average particle diameter of 5.2 μm (number variation coefficient: 24%, SF-1 = SF-1 = 105) was prepared and evaluated. Compared with Example 1, the OHP transparency and the like are the same, but the fixability is significantly reduced.
In the durability test under the condition of 60 ° C. and 60 ° C., the chargeability was gradually lowered to cause fog or the like to reach a practical level. Also S
Observation of the toner surface by EM revealed fine irregularities on the surface, which could be attributed to the pigment.

Example 2 The same as Example 1 except that the ester wax of the present invention in the formulation of Example 1 was changed to 28 parts by weight of wax F (maximum peak value 80.2 ° C .: manufactured by Hoechst). The same operation is performed to obtain a toner having a weight average diameter of 6.8 μm (number variation coefficient 42%, S
F-1 = 110) was produced and evaluated. Then, although there is no difference in the durability of 20,000 sheets as in Example 1, 3
In the durability test for 10,000 sheets under high temperature and high humidity of 0 ° C. and 80%, the charging property was gradually decreased. Further, although the image is clear and good with no scattering / fogging, the image density tends to increase slightly.

The copy had good light resistance, was of the 7th grade, and was excellent in fixability / OHP transparency.

Example 3 In the formulation of Example 1, the amount of ester wax added was 10
The amount of the emulsion polymerization liquid was changed to 3 parts by weight, and the number of rotations during granulation was changed to 13000 rotations to obtain an emulsion polymerization liquid. After obtaining, after changing to pH 4 and maintaining at 90 ° C., polymerize for 4 hours to aggregate,
Toner with a weight average diameter of 4.7 μm (number variation coefficient 47%,
SF-1 = 156) was obtained. When the same evaluation as in Example 1 was performed using the obtained toner, the image quality was slightly worse than that in Example 1, but the durability was 20,000 sheets.
Even after running 10,000 sheets under high temperature and high humidity, the chargeability was not deteriorated, and scattering / fog did not occur.

[0123]

[Table 1]

[0124]

INDUSTRIAL APPLICABILITY The toner of the present invention is not only excellent in heat resistance and light resistance, but it is possible to obtain a yellow toner having higher coloring and coloring power. In particular, in the suspension polymerization method of producing a toner by polymerizing in an aqueous medium, if the colorant has an affinity for water, the colorant is exposed on the toner surface, and a phenomenon such as fogging is likely to occur. However, by combining with the ester wax of the present invention, a toner excellent in charging property, fixing property and OHP transparency can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic view of a tomographic plane of a toner of the present invention in which an ester wax is encapsulated in an outer shell resin.

Claims (5)

[Claims] 1. A toner obtained by directly polymerizing a composition containing at least a polymerizable monomer, a wax and a colorant in an aqueous medium, wherein the toner has a weight average diameter of 9 μm or less, and the wax is A color toner for developing an electrostatic charge image, comprising an ester wax, and the colorant having a skeleton represented by the following structural formula. Embedded image 2. The color toner for developing an electrostatic charge image according to claim 1, wherein the wax has one or more long chain ester moieties having 15 or more carbon atoms. 3. The wax and the colorant are contained in an amount of 5 to 30% by weight and 1 to the resin component in the toner, respectively.
1 to 2 are contained.
The color toner for developing an electrostatic charge image according to item 1. 4. The electrostatic toner for developing an electrostatic image according to claim 1, wherein the ester wax contains any of the substances represented by the following general formula as a main component. Embedded image (A, b: an integer of 0 to 4 and a + b = 4 R ₁ , R ₂ : an organic group having an integer of 1 to 40 carbon atoms, and the difference in carbon number between R ₁ and R ₂ is 3 Above m and n are integers from 0 to 25, and m and n cannot be 0 at the same time.) (A, b: an integer from 0 to 4, a + b = 4, b ≠ 0 R ₁ : an organic group having an integer of 1 to 40 carbon atoms, m, n: an integer from 0 to 25, m and n cannot be 0 at the same time.) (A, b: integers from 0 to 3 and 1 ≦ a + b ≦ 3 R ₁ and R ₂ : organic groups having an integer from 1 to 40, and the difference in carbon number between R ₁ and R ₂ Is 3 or more R ₃ : a hydrogen atom, an organic group having 1 or more carbon atoms, provided that a
When + b = 2, one of R ₃ is an organic group having 1 or more carbon atoms, k: an integer from 1 to 3, m and n: an integer from 0 to 25, and m and n are 0 at the same time. It never happens. ) 5. A transmission electron microscope (TEM) of the toner.
5. The toner cross-sectional layer is observed by using, and the ester wax is encapsulated in an outer shell resin layer, and the shape factor SF-1 measured by Luzex shows 100 to 130. 5. A color toner for developing an electrostatic charge image as described in 1.